DE889299C - Process for the preparation of hydrogenated compounds with the formylpteroic acid nucleus - Google Patents

Description

Process for the preparation of hydrogenated compounds with the formylpteroic acid nucleus The invention relates to the preparation of hydrogenated compounds having the formylpteroic acid nucleus.

In 1948, Sauberlich and Baumann [cf. Journal of Biological Chemistry, 176, p. 165 (z948)] the existence of a substance which promotes growth stimulated by Leuconostoc citrovorum in a synthetic medium. It was found, that this unknown substance in commercial liver extracts and also in the Liver and a variety of natural materials is present. It got on found that the unknown substance meets the folinic acid requirement in microorganisms and Chick can replace. It was also found that the growth factor has the effect of pteroylglutamic acid antagonists and, surprisingly, the toxic ones Effects of 4-aminopteroylglutamic acid or aminopterin, N- [p - @ [(2, 4-diamino-6-pyrimido- [4, 5-b] -pyrazyl) -methyl] -amino @ -benzoyl] -glutamic acid, in mice and bacteria under conditions where pteroylglutamic acid is ineffective.

The citro vorum factor occurs in extremely low levels in natural products Quantities, so that its extraction from it is extraordinary from an economic point of view difficult and practically impossible. It has been found, however, that it can is to produce compounds by an economical process, the related possess biological activity.

The hydrogenated compounds with the formylpteroic acid core according to the invention are prepared by adding a -formylated compound of the general formula or a salt thereof is hydrogenated. In the above formula, X is an amino or alkylamino radical, R is a hydroxyl or amino acid radical, and R1 and R2 are hydrogen or halogen atoms. The case where X is amino and R1 and R2_ are both hydrogen is excluded.

In the above formula, R is intended to be a hydroxyl group or the radical one Mean amino acid. This amino acid is preferably glutamic acid or a peptide of glutamic acid, such as glutamylglutamic acid, glutamylglutamylglutamic acid, hexaglutamylglutamic acid or glycylglutamic acid. However, the amino acid radical can also be from another Amino acids, for example from aspartic acid, glycine, alanine, dl-isoleucine, dl-valine or serine. Since the amino acids contain carboxyl groups, salts can also be used of these compounds can be used in the process if desired.

The exact structure of the new compounds made by reducing the above formyl compounds has not yet been finally determined in view of their insanely complex nature. However, it can be assumed that they can be represented by one of the following formulas: In these structural formulas, X, R, R1 and R2 have the meanings given above. It should also be noted that the above compounds can exist in tautomeric forms, depending on the conditions under which they are present. As explained, the compounds can exist in the open form (I) or in the tautomeric, closed form (II). The reduction of the formyl compounds, whereby the new products according to the invention are prepared, can either with or without the aid of catalysts. take place. In the case of catalytic reduction, a variety of solvents such as water, formic acid, alcohols, glycol, acetic acid or dimethylformamide can be used, depending on the nature of the catalyst used. The reduction temperature can extend over a wide temperature range; temperatures of about 0 ° to about rgo ° are preferred. The p, u can vary over a wide range (in an aqueous medium) from about pH 3 to pH 12.

Many reduction catalysts can be used in the process such as platinum black, palladium on activated carbon or Raney nickel, which further are described below.

In general, implementation is fairly rapid; it can be done in zo minutes at room temperature using e.g. B. platinum in formic acid considerable yields of the desired product can be obtained. The reduction is usually complete in a period of 30 minutes to about 2 hours, but it can also q. Take hours and longer.

Generally the preferred method of making the new invention Connections is the following: The substituted 4-aminopteridines are first Formylated in go to 100 ° Joiger formic acid at 0 to 100 °. The so produced Formyl compounds can, if desired, be isolated and then the reduction in one other solvents. However, it is generally more convenient to to follow up the reduction in the same solution by adding the catalyst to the solution, after which hydrogen is passed into the reaction mixture with shaking or stirring will. In some cases it can be advantageous to add the catalyst before mixing with the substituted formylated pteridine to activate with hydrogen, though this measure is not necessary. The hydrogen pressure in the reaction vessel can be from z to zoo atm. or more; however, under ordinary conditions a pressure of 2 to 3 atm. sufficient to achieve a good yield. To the reduction, the catalyst is removed by filtration and the solution with aqueous alkali, such as an aqueous solution of sodium bicarbonate, buffered. if it is desirable to remove the excess formic acid from the reducing solution after Removal to remove the catalyst, the solution can be poured into ether and the insoluble biologically active product isolated by filtration or the solvent removed by distillation and the residue recovered.

If reduction methods using metals or combinations of metals, such as sodium amalgam, zinc, aluminum amalgam, sodium borohydride, magnesium amalgam or Magnesium, are applied, it will usually be water or an essentially aqueous solvent used.

The reduced substituted formylpteridine, as described above can be made to various absorbent means, such as Activated carbon or magnesium silicate. These measures can be used to Purification of the crude reaction products by chromatographic adsorption methods can be applied.

The following examples illustrate various methods of preparation of the biologically active substances according to the invention by reducing certain substituted Formylpteridines. Unless otherwise stated, all parts are amounts by weight is. Example i 2 parts of 4-aminopteroylglutamic acid of 73% purity become Heated in 40 parts of 98 to 100% formic acid on the steam bath for 1 hour. Half of this solution is poured into sodium bicarbonate solution and saved. The remainder is 2 hours with 0.25 parts of platinum oxide catalyst at 15.87 kg (351bs.) Hydrogen pressure reduced. The platinum is filtered off and the solution in sodium bicarbonate solution poured. This reduced product shows a growth inhibiting effect against various Bacteria. Example 2 The procedure of Example i is repeated with the exception that the 4-aminopteroylglutamic acid in 98 to 100% formic acid for 2 hours is stirred at 2o to 25 °. The resulting solution gives after the reduction and Isolation of the product as described in Example i, a product that has a similar has a growth-inhibiting effect against certain bacteria.

Example 3 0.5 part of 2-N, N-dimethylamino-4-aminopteroylglutamic acid are dissolved in 2o parts of 98 to 100% formic acid and i hour on the Steam bath heated. After cooling to room temperature, 0.1 parts of platinum oxide catalyst are used and the mixture at 15.87 kg (35 lbs.) hydrogen pressure for 2 hours reduced. The platinum is filtered off and the solution poured into 300 parts of water, which contains excess sodium bicarbonate. The solution is clarified and adjusted to PH 4 is set, after which io parts activated carbon are added. After stirring for 1/2 hour at room temperature the mixture is filtered and the activated charcoal cake with ammonia-ethanol mixture extracted. This is then evaporated to dryness and the residue with an ethanol-ether mixture treated. A pale yellow ammonium salt separates from reduced 2-N, N-dimethylamino-4-amino-Nlo-formylpteroylglutamic acid from, which, after filtering off and drying under reduced pressure, weighs 0.15 parts. It has an anti-growth effect.

Example 4 i Part 3 ', 5'-dichloro-4-aminopteroylglutamic acid dissolved in 20 parts of 98 to 100% formic acid and put on the steam bath for 45 minutes heated to form a clear yellow solution. After cooling to room temperature o, 2o parts of platinum oxide catalyst are added; then the mixture is at 15.87 kg (35 lbs.) of hydrogen pressure reduced for 1/2 hour. The platinum is filtered off and the solution poured into 300 parts of water, the excess sodium bicarbonate contains. Then it is adjusted to pl.4, 10 parts of activated charcoal are added and the mixture stirred for 1/2 hour. The activated charcoal is then filtered off and mixed with ammonia and ethanol extracted. The resulting solution is evaporated to dryness under reduced pressure and the residue was taken up in 10 parts of water, giving a clear solution. This is set to Pu 7; then a concentrated, 0.4 part of barium chloride containing solution was added and then 40 parts of ethanol. It becomes a white barium salt the reduced 3 ', 5'-dichloro-4-amino-Nlo-formylpteroylglutamic acid precipitated; Dry weight o.5i parts. It inhibits the growth of certain bacteria.

Example 5 This reaction is carried out in the same manner as described in Example 14. 0.57 parts of the yellow barium salt of the reduced 4-amino-Nlo-formylpteroylaminomalonic acid are obtained from 1 part of 4-aminopteroylaminomalonic acid. It has a growth-inhibiting effect against bacteria. Example 6 This reaction is carried out in the same manner as described in Example 14. From one part of 4-aminopteroyl-d, i-isoleucine, 0.17 parts of the yellow barium salt of the reduced 4-amino-Nlo-formylpteroyl-d, i-isoleucine are obtained. It has a growth-inhibiting effect.

Example 7 This reaction is carried out in the same manner as described in Example 14. 0.35 parts of the yellow barium salt of the reduced 4-amino-Nlo_formylpteroyl-d, i-valine are obtained from 1 part of 4-aminopteroyl-d, i-vahn. It has a growth-inhibiting effect.

Claims (3)

PATENT CLAIMS: i. Process for the preparation of hydrogenated compounds with the formylpteroic acid core, characterized in that a formylated compound of the general formula or a salt thereof is hydrogenated; X is an amino or alkylamino radical, R is a hydroxyl or amino acid radical and R1 and R2 are hydrogen or halogen atoms, except for the case where X = amino and R1 and R2 are both hydrogen. 2. The method according to claim i, characterized in that the hydrogenation made in an inert solvent in the presence of a reducing catalyst will. 3. The method according to claim r and 2, characterized in that the reaction is carried out at a temperature between 0 and 15o °. q .. method according to claim 1 to 3, characterized in that the formylated compound is made without it to isolate the reaction mixture formed during their preparation, reduced directly.